The present invention relates to lead perovskite-based ceramic dielectric compositions with high dielectric constants (K), e.g., above about 8000; low dissipation (loss) factors (DF), e.g., below about 3%; ultra low sintering temperatures, e.g., below about 1050.degree. C.; which may be sintered without any external atmosphere control and which contain no free lead oxide.
The high dielectric constants and low dissipation factors of the ceramic compositions of this invention make them suitable for the manufacture of multilayer ceramic capacitors, hereinafter called MLCs, having high capacitances and small physical sizes. With their ultra-low sintering temperatures, the ceramic compositions of the present invention are suitable for manufacturing MLCs utilizing metal internal electrodes of the lower melting point metals and their alloys, such as 70% Ag; 30% Pd, which are significantly cheaper than the noble metals commonly used for such electrodes. No external atmosphere control is required for these compositions so they are suitable for manufacturing MLCs with simple kiln equipment. Most significantly, because the compositions of the present invention do not contain free lead oxide, which is harmful by ingestion and inhalation, they are easier to handle and process. The ceramic compositions of this invention therefore enable the manufacture of high performance, high volume efficiency MLCs with simplified manufacturing processes and lower costs.